We love harvesting fresh greens for salads right from our raised garden beds. Here in Connecticut, lettuce is one of our favorite crops to grow in the early spring and fall when outdoor temperatures are between 50°F and 70°F. Being a cool weather crop, lettuce doesn’t fare well with the intense heat of summer. We find that lettuce is an incredibly easy and rewarding vegetable to grow in the garden, and we’re excited to share all of our best growing tips with you.
We’ve grown lettuce in pots outdoors and even indoors hydroponically. However, our favorite way of growing lettuce is outdoors in our raised beds. In the spring, lettuce is the perfect crop to kickstart the garden season. Then, when fall rolls around and our summer crops are finished producing, we clear out our garden and make room for more lettuce!
Types of lettuce to grow in your raised bed
- Romaine (Cos lettuce) – Crisp and sweet with a wonderful flavor and texture. Great to use in salads or sandwiches. Some varieties are heat tolerant and will maintain their flavor through hot spells.
- Butterhead (Bibb lettuce) – Slightly sweet with a more mild flavor with delicate, soft leaves. Easy to grow in raised beds, especially if you’re using row covers. Probably our favorite lettuce to grow.
- Loose-leaf – Comes in many varieties from red to green. Does not form a compact lettuce head like other types, grows in a loose rosette pattern.
- Crisphead (Iceberg) – The crunchiest of all lettuces. Requires a longer period of cool weather and takes the longest to mature. We think it’s worth the wait!
When to plant lettuce for raised beds
When deciding when to plant lettuce for your raised bed, there are a few factors to consider. You may want to plant lettuce once a season, or you may choose to plant in both the spring and the fall.
If you do not have the space or time to start seeds indoors, you can buy lettuce transplants at your local garden center. Often, they have a great variety of options to choose from. If you decide to buy transplants, you can still follow the general planting guidelines below, just skip the process of starting the seeds indoors and move right to transplanting.
- If starting lettuce indoors for for spring, start lettuce seeds in containers or flats about 6 weeks before your last frost date. Find your frost dates here. We have also found that bottom watering our lettuce is best. Place them under grow lights and bring them outdoors when they are 3 weeks old. Be sure to harden them off for a few days (expose them to the outdoor climate gradually) before transplanting them into the ground.
- For example, here in zone 6 our schedule is as follows: Start seeds indoors around March 20th, bring them outside April 10th to harden off, and again for a few more days. Transplant into the ground around April 15th-April 20th.
- If direct sowing outdoors in spring, sow lettuce directly outdoors about 2 weeks before your last spring frost.
- For example, here in zone 6 we direct sow lettuce outdoors around April 15th.
- If starting lettuce indoors for fall, sow lettuce seeds in containers or flats about 6 weeks before your first frost date. Keep in mind that you don’t need to start your lettuce seeds indoors for fall planting (see direct sowing below). We don’t use grow lights in the fall, as the seeds sprout just fine by a warm and sunny window. As soon as the seeds sprout, we bring the seed cells outside and allow the lettuce to continue growing in their containers. After 2-3 weeks, we transplant them into the ground.
- For example, here in zone 6 our schedule for fall planting lettuce is as follows: Start seeds indoors on windowsill around August 20th. Bring them outside as soon as they sprout. Transplant them into the ground after a couple weeks.
- If direct sowing outdoors for fall harvest, direct sow the seeds at 10 day intervals starting 6-8 weeks before your fall frost. This will give you a continuous succession of fresh lettuce. Starting about 4 weeks before your fall frost, sow varieties that are more cold-tolerant. Make a trench (about 1/4 inch deep) in moist soil, and sprinkle your lettuce seeds in. You can thin them to be 6 inches apart as the sprouts grow in.
- For example, here in zone 6 our schedule for direct sowing lettuce outdoors in fall is as follows: Start direct sowing around August 20th. August 30th, sow another round of lettuce seeds. Around September 14th, sow another round of lettuce seeds (cold-tolerant varieties only).
Tip: Plant lettuce with good companions. Arugula, spinach, onions, and marigolds all pair well with lettuce.
How to plant lettuce for raised beds
Ideally, your raised bed will be situated in a spot that gets plenty of sun. Lettuce does best with well-draining soil that is kept moist and cool. When preparing your raised bed for lettuce, loosen the soil at least 6 inches deep. Then, mix in some compost to give your lettuce a strong start.
- If transplanting lettuce seedlings in spring: plant your lettuce transplants directly in your raised bed 2-3 weeks before your last spring frost, giving them around 6 inches to spread out. If there is an unexpected hard frost, protect your young plants with a floating row cover. Here in zone 6, our lettuce transplants get placed in the ground around April 15th. We also direct sow lettuce seeds at that time so we have a continuous succession of fresh greens.
- If direct sowing lettuce outdoors in late summer/fall: you can direct sow lettuce seeds 1/4 inch deep and about 1 inch apart. Use a pencil to make a trench and generously sprinkle the seeds in. Lettuce seeds require light to germinate, so don’t bury them, just press them into the surface. After sprouting, thin the seedlings to 6 inches apart. As mentioned above, start this process 6-8 weeks before your fall frost.
Tip: Use a half-strength fertilizer after transplanting your lettuce seedlings. At this point they should be at least 3 inches tall.
Common problems when growing lettuce in a raised bed
No garden goes without its share of issues. From pests to critters and disease, there are many things that can go wrong when growing lettuce. Keep in mind, these issues are not limited to growing lettuce in raised beds.
- Edges of lettuce are brown and dry: If you notice browning at the edges of your lettuce, or dark/slimy leaves, you may have tipburn. This typically happens during the summer months and is the result of lettuce plants not receiving enough water. Be sure to provide your lettuce with plenty of water, plant only in the spring and fall, and choose varieties that are resistant to tipburn if it is a common problem for you. Starfighter , Green Forest and Tropicana are good options that are tolerant to tipburn.
- Lettuce grows very tall with bitter leaves: When the weather is too warm, lettuce grows tall with tough/bitter tasting leaves. The lettuce grows prematurely and sets seed – also known as “bolting.” Be sure to grow lettuce only in cool conditions, harvest regularly, or plant bolt-resistant varieties.
- Aphids feeding between lettuce folds: Aphids can be easily sprayed off with a good blast of water from the hose. You can also attract beneficial insects to keep populations under control.
- Slugs and snails: If you notice irregular shaped holes on the outer edges of your lettuce leaves, slugs may be to blame. You can try using a commercial slug/snail bait, or create your own traps with oil or beer. Handpicking the slugs from the lettuce is also an effective (but time-consuming) way to control them. There is also some evidence showing that coffee grounds are effective at deterring them.
Tip: Lettuce likes moist soil! Water carefully and close to the bottom to prevent soil splatter and fungal issues.
Lettuce growth stages
Like any plant, lettuce goes through many stages of growth. It all starts with a single seed! Here’s what happens after you plant your lettuce seeds:
Stage 1 – Germination – Between 2 and 8 days you’ll begin to see your lettuce sprouting. How exciting! After anxiously checking your seeds every few hours (oh, is that just us?), you finally have a sprout. Leaves and roots begin forming.
Stage 2 – Seedling – Leaves are beginning to grow and your lettuce is off to a great start. You’ll begin seeing the rosette pattern during this stage. It’s especially important during this stage to protect your young seedlings from pests and animals, as the leaves are quite tender. Seedlings are transplanted during this stage outdoors when they reach 3-4 inches tall.
Stage 3 – Lettuce head formation – Your seedlings are beginning to form a lettuce head. At this point you can fertilize them and wait for them to grow to their full size. It’s important to be vigilant about pests at this point.
Stage 4 – Maturity/harvest – It’s time to feast! You always want to make sure you harvest your lettuce before it bolts. Harvesting your lettuce will depend on the variety that you grew. Some lettuce, like loose-leaf and butterhead, can mature in as little as 45 days. Crisphead lettuce (like iceberg) can take as long as 90 days to mature.
Cold tolerant lettuce varieties
We understand. You want your gardening season to last as long as possible. Here in zone 6, our first frost is in October. That doesn’t stop us from growing lettuce and other leafy greens for many more weeks! Here are some great varieties of lettuce that are cold-tolerant.
- Winter Density – A sweet romaine with delicate leaves. Heat and cold tolerant. 44 days to maturity.
- North Pole – A sweet butterhead that thrives in cooler climates. While it is cold hardy, it will bolt in the summer heat so its best planted later in the season. 50 days to maturity.
- Ice Queen – A cold tolerant variety that dates back to the 1800s. Quick to mature (you can harvest the outer leaves and use them in salads). Also heat tolerant/slow to bolt making it a great option for early spring planting as well.
- Black Seeded Simpson Leaf – Baby greens can be harvested in just a few weeks. Great texture and flavor and also withstands light frosts.
How to harvest lettuce
Now that all that hard work is done, it’s time for the payoff! Harvest time is the best time, isn’t it? The way you harvest your lettuce all depends on the type you grew. Most lettuces can be harvested as they grow. The outer leaves are plucked away for salads while the remainder of the center continues to form. This is called “cut and come again.”
It all depends on your preference. Whether you prefer fresh greens on a daily basis, or you’re looking to pluck the entire head and make room in the garden, here are some basic guidelines for harvesting different types of lettuce:
- Harvesting romaine lettuce – The outer leaves of romaine lettuce can be harvested while the center of the head continues to grow. You’ll want to wait for the leaves to start overlapping, reaching lengths of about 6 inches. You can also pull up the entire head at once.
- Harvesting butterhead lettuce – Similar to romaine, you can harvest the outer leaves of butterhead lettuce as it grows. You’ll want to wait until the outer leaves become large and ruffled. Using sharp pruning shears is helpful for harvesting with precision. You can also wait until the head is completely grown and harvest it all at once.
- Harvesting loose-leaf lettuce – Loose-leaf lettuce can be harvested as soon as the leaves are about 3 inches long.
- Harvesting crisphead lettuce – With crisphead lettuce, we prefer to to harvest the entire head at once. Maturity for this lettuce takes the longest. Be sure to harvest the whole head as soon as it’s ready.
Tips for growing lettuce in raised beds
- While lettuce seeds can remain viable after many years, we suggest replacing them after 1 year for the best germination rates.
- If you have limited space to work with, try growing smaller varieties like Little Gem.
- Use shade cloth in the heat of the summer to extend your spring growing season. Row cover can also be used to protect young seedlings from harsh frosts.
Hopefully this post helped inspire you to try growing lettuce in your raised bed. It’s one of our favorite vegetables, and it’s truly so easy to grow! Let us know in the comments what varieties you have had success with, or if you have any tried-and-true tips for growing lettuce.